1. Field of the Invention
The present invention relates to a rolling device of an oil lubricated type and, more particularly, to a status monitoring system and a status monitoring device both associated with such rolling device of the particular type.
2. Description of Related Art
Some abnormality predications for bearing assemblies are currently available. In this respect, see, for example, the patent document 1 listed below. One of those abnormality predication includes measuring the degradation of a lubricant to thereby predicate the lifetime of the bearing assembly. Deterioration of the lubricant results in a reduction in thickness of an oil film at a contact portion within the bearing assembly, which leads to the bearing assembly susceptible to abrasion and/or surface damage. Accordingly, through the measurement of a deteriorated condition of the lubricant, reduction of the lifetime of the bearing assembly is monitored and predicated.
When rolling component part parts for use with rolling bearing assemblies and gears are used under a condition in which water may ingress (such as discussed in the non-patent documents 1 to 5 listed below) or under a condition in which they tend to be subjected to slide (such as discussed in the non-patent document 6 listed below), water or the lubricant is dissolved to generate hydrogen and, if the resultant hydrogen intrudes into a steel material, damages may arise quickly. Once a metal contact occurs at a contact surface between contact elements to such an extent as to allow a newly-formed metal surface to be exposed, generation of hydrogen as a result of decomposition of water and the lubricant and subsequent intrusion of hydrogen into the steel material will be accelerated. This is evidences by the experimental fact that consequent upon the temperature programmed hydrogen desorption analysis performed after a steel material used to form the rolling component part parts were subjected to abrasive wear with the use of a emery paper, while water and the lubricant had been supplied dropwise, diffusible hydrogen was palpably detected from the steel material used (such as discussed in the non-patent document 7 listed below). According to the analysis referred to above, a more amount of the diffusible hydrogen was detected when water, rather than the lubricant oil, was supplied dropwise. Accordingly, it may be regarded that when water is mixed in the lubricant for the rolling component part parts that are used under a condition in which a sliding motion takes place, hydrogen is further generated and is apt to intrude into the steel material. Since hydrogen is responsible to a considerable reduction in fatigue strength of the steel material (such as discussed in the patent document 8 listed below), the intrusion of hydrogen leads to a rapid damage even under the maximum contact surface pressure that is not so high.